Methods and apparatus to determine synthetic respondent level data using constrained markov chains

ABSTRACT

Methods, apparatus, systems, and articles of manufacture are disclosed to generate synthetic respondent level data. An example method includes generating a first and second synthetic panel corresponding to a first duration of time based on a seed panel and first duration constraints; generating synthetic respondent level data corresponding to a second duration of time by linking synthetic panelists from the first synthetic panel to the second synthetic panel; and generating an output file based on the synthetic respondent level data.

FIELD OF THE DISCLOSURE

This disclosure relates generally to media audience measurement, and,more particularly, to methods and apparatus to determine syntheticrespondent level data using constrained Markov chains.

BACKGROUND

Determining a size and demographic of an audience of a mediapresentation helps media providers and distributors schedule programmingand determine a price for advertising presented during the programming.In addition, accurate estimates of audience demographics enableadvertisers to target advertisements to certain types and sizes ofaudiences. To collect these demographics, an audience measurement entityenlists a plurality of media consumers (often called panelists) tocooperate in an audience measurement study (often called a panel) for apredefined length of time. In some examples, the audience measuremententity obtains (e.g., directly, or indirectly via a service provider)return path data from media presentation devices (e.g., set-top boxes)that identifies tuning data for the respective media presentationdevices. In such examples, the audience measurement entity models and/orassigns viewers based on the return path data. The media consumptionhabits and demographic data associated with these enlisted mediaconsumers are collected and used to statistically determine the size anddemographics of the entire audience of the media presentation. In someexamples, this collected data (e.g., data collected via measurementdevices) may be supplemented with survey information, for example,recorded manually by the presentation audience members.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example environment in which return pathdata and meter data are collected from media presentation locations andare analyzed by an example audience measurement entity to generate anexample seed panel and generate example synthetic respondent level databased on the example seed panel in accordance with the teachings of thisdisclosure.

FIG. 2 is a block diagram of an example implementation of an examplesynthetic panel generator of FIG. 1.

FIG. 3 is a block diagram of an example implementation of an exampledaily synthetic panel generator of FIG. 2.

FIG. 4 is a block diagram of an example implementation of an exampleextended synthetic panel generator of FIG. 2.

FIGS. 5-7 are flowcharts illustrating example machine readableinstructions that may be executed to implement the example syntheticpanel generator of FIGS. 1 and/or 2.

FIG. 8 is a block diagram of an example processing system structured toexecute the example machine readable instructions of FIGS. 5-7 toimplement the example synthetic panel generator of FIGS. 1 and/or 2.

DETAILED DESCRIPTION

Audience measurement entities seek to understand the composition andsize of audiences of media, such as television programming. Suchinformation allows audience measurement entity researchers to, forexample, report advertising delivery and/or targeting statistics toadvertisers that target their media (e.g., advertisements) to particularaudiences. Additionally, such information helps to establish advertisingprices commensurate with audience exposure and demographic makeup(referred to herein collectively as “audience configuration”). One wayto gather media presentation information is to gather the mediapresentation information from media output devices (e.g., gatheringtelevision presentation data from a set-top box (STB) connected to atelevision). As used herein, a media presentation includes media outputby a media device regardless of whether or not an audience member ispresent (e.g., media output by a media output device at which noaudience is present, media exposure to an audience member(s), etc.).

A media presentation device (e.g., STB) provided by a service provider(e.g., a cable television service provider, a satellite televisionservice provider, an over-the-top service provider, a music serviceprovider, a movie service provider, a streaming media provider, etc.) orpurchased by a consumer may contain processing capabilities to monitor,store, and transmit tuning data (e.g., which television channels aretuned by the media presentation device at a particular time) back to theservice provider, which may provide at some of the tuning data (e.g.,after aggregation and/or other post-processing) to an audiencemeasurement entity (e.g., The Nielsen Company (US), LLC.) to analyzemedia presentation activity. Data transmitted from a media presentationdevice back to a service provider providing the media (which may thenaggregate and provide the return path data to an audience measuremententity) is herein referred to as return path data. Return path dataincludes tuning data. Tuning data is based on data received from themedia presentation device while the media presentation device is on(e.g., powered on, switched on, and/or tuned to a media channel,streaming, etc.). Although return path data includes tuning data, returnpath data may not include data (e.g., demographic data) related to theuser viewing the media corresponding to the media presentation device.Accordingly, return path data may not be associated with particularviewers, demographics, locations, etc.

To determine aspects of media presentation data (e.g., which householdmember is currently consuming a particular media and the demographics ofthat household member), market researchers may perform audiencemeasurement by enlisting a subset of the media consumers as panelists.Panelists or monitored panelists are audience members (e.g., householdmembers, users, panelists, etc.) enlisted to be monitored, who divulgeand/or otherwise share their media activity and/or demographic data tofacilitate a market research study. An audience measurement entitytypically monitors media presentation activity (e.g., viewing,listening, etc.) of the monitored panelists via audience measurementsystem(s), such as a metering device(s) and/or a local people meter(LPM). Audience measurement typically includes determining the identityof the media being presented on a media output device (e.g., atelevision, a radio, a computer, etc.), determining data related to themedia (e.g., presentation duration data, timestamps, channel data,etc.), determining demographic information of an audience, and/ordetermining which members of a household are associated with (e.g., havebeen exposed to) a media presentation. For example, an LPM incommunication with an audience measurement entity communicates audiencemeasurement (e.g., metering) data to the audience measurement entity. Asused herein, the phrase “in communication,” including variances thereof,encompasses direct communication and/or indirect communication throughone or more intermediary components and does not require direct physical(e.g., wired) communication and/or constant communication, but ratheradditionally includes selective communication at periodic or aperiodicintervals, as well as one-time events.

In some examples, metering data (e.g., including media presentationdata) collected by an LPM or other meter is stored in a memory andtransmitted via a network, such as the Internet, to a datastore managedby the audience measurement entity. Typically, such metering data iscombined with additional metering data collected from a plurality ofLPMs monitoring a plurality of panelist households. The metering datamay include, but are not limited to, a number of minutes a householdmedia presentation device was tuned to a particular channel, a number ofminutes a household media presentation device was used (e.g., consumed)by a household panelist member and/or a visitor (e.g., a presentationsession), demographics of the audience (which may be statisticallyprojected based on the panelist data), information indicative of whenthe media presentation device is on or off, and/or informationindicative of interactions with the media presentation device (e.g.,channel changes, station changes, volume changes, etc.), etc. As usedherein, a channel may be a tuned frequency, selected stream, an addressfor media (e.g., a network address), and/or any other identifier for asource and/or carrier of media.

Return path data provides valuable media exposure data, including mediaexposure data in locations where no panel data is available. However,return path data typically contains tuning data in the aggregate.Accordingly, return path data usually does not include respondent leveldata such as, but not limited to, detailed data relating to audiencedemographics and/or viewing data broken up into margins (e.g., quarterhours). Examples disclosed herein alleviate the lack of respondent leveldata in return path data by leveraging the respondent level dataobtained from a panel of monitored panelists. Using examples disclosedherein, synthetic respondent level data corresponding to a group ofsynthetic, or virtual, panelists may be generated to correspond to thereturn path data, thereby increasing the value of return path data to acustomer (e.g., of an advertising company).

Examples disclosed herein process the collected and/or aggregatedmetering data for markets where a panel is maintained and collect and/oraggregate return path data for markets where a panel is not maintainedto generate a seed panel. A seed panel is a synthetic panel includingmonitored panelists and/or any other users (e.g., in which demographicdata is known) selected to correspond to return path data homes (e.g.,in-market return path data) and regional panel homes (e.g., over the aironly panelists) and used as the basis for generation of syntheticrespondent level data (e.g., representative of a group ofsynthetic/virtual panelists) corresponding to the return path data.These monitored panelists are selected from a panel (e.g., a nationalpanel of metered users) based on a regional proximity to a designatedmarket area, a similarity between demographics of the monitored panelistand demographics of the return path data audience location, householdmedia characteristics (e.g., how the households receive televisionsignals (cable, satellite, over-the-air radio, etc.)), a similaritybetween media consumption of the monitored panelists and the return pathdata audience, etc. As used herein, a return path data audience isviewer assigned return path data associated with a population (e.g., auniverse or users) and/or location. As used herein, a seed panelist is amonitored panelist that has been selected to be included in a seedpanel. As used herein, synthetic respondent level data or respondentlevel data is processed viewing data at the level of individualrespondents. Synthetic respondent level data may include complete timerecords (e.g., at the quarter hour level, hour level, etc.) across eachbroadcasting day of all viewing sessions by every family member andguest on all metered media output devices in a home including thedemographic data. As used herein, designated market area is ageographical area that defines a media market where synthetic respondentlevel data is produced.

Once a seed panel has been generated, examples disclosed herein adjustthe seed panel to satisfy constraints (e.g., daily target reach, weeklytarget reach, monthly reach, etc.). As used herein, reach is acumulative percentage or total of a population that has been counted asa viewer of media at least once during a specified time interval (e.g.,daily, weekly, monthly, etc.). Examples disclosed herein generatetransition matrices based on seed panel data. The transition matrixincludes transition data corresponding to the likelihood (e.g.,probability) that a panelist will switch from one program, channel,etc., to another within a quarter hour. Examples disclosed hereingenerate synthetic panels corresponding to a first duration of time(e.g., a daily panel) by generating viewing data according to thetransition matrices. To satisfy a target reach corresponding to knownaggregate data for the day, examples disclosed herein weigh the viewingdata of the synthetic panelists based on the target reach (such as thetarget reach represented by the aggregate return path data) until thetarget reach is satisfied. For example, if the target reach (e.g.,corresponding to a reach reflected in the aggregate return path data) is250,000 viewers exposed to a first program during a first duration oftime and 300,000 of the generated seed panelist were exposed to thefirst program during the first duration of time, examples disclosedherein generate synthetic panelist data based on the seed panel toreduce the synthetic reach (e.g., 300,000) to a rating closer to thetarget reach (e.g., 250,000). In some examples, to select syntheticpanelists that are a better fit for the constraints (e.g., reaches),examples disclosed herein remove synthetic panelists from the dailysynthetic panel whose weights are below a threshold value.

Further, examples disclosed herein generate synthetic respondent leveldata for extended durations of time (e.g., longer than the firstduration) by gathering daily synthetic panels corresponding to theextended duration of time and linking the panelists across the dailypanelist to satisfy extended constraints. Examples disclosed hereingenerate an output file including synthetic respondent level datacorresponding at least one of daily synthetic respondent level panel,weekly synthetic respondent level data, monthly synthetic respondentlevel data, etc. Using examples disclosed herein, consistent respondentlevel data is generated that satisfy various targets, thereby providingmore accurate universe estimations.

FIG. 1 is a block diagram of an environment in which example return pathdata 100 and example meter data 102 are collected to generate syntheticrespondent level data based on a generated seed panel. FIG. 1 includesthe example return path data 100, the example meter data 102, an examplemedia provider 104, an example media presentation device 106, examplemedia output devices 108, 110, an example local people meter (LPM) 112,and an example audience measurement entity (AME) 114. The exampleaudience measurement entity 114 includes an example modeler 116, anexample return path data (RPD) audience storage 118, an example panelistdata storage 120, an example seed panel generator 122, an examplestation data storage 124, an example seed panel storage 126, an examplesynthetic panel generator 128, and an example output file 130.

The example media provider 104 of FIG. 1 is a service provider (e.g.,cable media service provider, a radio frequency (RF) media provider, asatellite media service provider, etc.) that presents media to anaudience member via the example media presentation device 106. The mediaprovided by the example media provider 104 is transmitted (e.g., via awired or wireless network connection) to the media presentation device106. The media presentation device 106 is connected, via a wired orwireless connection, to the example media output device 108 to outputthe media to an audience member. The media output device 108 is a devicecapable of outputting the received media. For example, the media outputdevice 108 may be a television, a radio, speakers, a projector, acomputer, a computing device, a tablet, a mobile device, and/or anyother device capable of outputting media.

When the example media presentation device 106 of FIG. 1 is on, themedia presentation device 106 receives media corresponding to a station,program, website, etc., based on the tuning of the example mediapresentation device 106. For example, the media presentation device 106may be a set-top box. Additionally or alternatively, the example mediapresentation device 106 may be an over-the-top device, a video gameconsole, a digital video recorder (DVR), a digital versatile disc (DVD)player, a receiver, a router, a server, a computer, a mobile device, asmart television, and/or any device that receives media from a serviceprovider. In some examples, the media presentation device 106 mayimplement a DVR and/or DVD player. In some examples, the example mediapresentation device 106 includes a unique serial number that, whenassociated with subscriber information, allows an audience measuremententity, a marketing entity, and/or any other entity to ascertainspecific subscriber behavior information.

By way of example, the example media presentation device 106 may betuned to channel 5. In such an example, the media presentation device106 outputs media (from the example media provider 104) corresponding tothe tuned channel 5. The media presentation device 106 may gather tuningdata corresponding to which channels, stations, websites, etc., that theexample media presentation device 106 was tuned. The example mediapresentation device 106 generates and transmits the example return pathdata 100 to the example media provider 104. The example return path data100 includes the tuning data and/or data corresponding to the examplemedia provider 104 (e.g., data in the aggregate). Although theillustrated example of FIG. 1 includes the example media provider 104receiving the example return path data 100 from one media presentationdevice (e.g., the example media presentation device 106), at onelocation, corresponding to one media provider (e.g., the example mediaprovider 104), the example media provider 104 may receive return pathdata 100 (e.g., after post-processing, such as aggregation, obfuscation,etc., to remove personal identification information (PH) data) from anynumber or type(s) of media presentation devices, at any number oflocations. The media provider 104 transmits the collected return pathdata 100 to the example audience measurement entity 114. Additionally oralternatively, the audience measurement entity 114 may be hosted by anyother entity or may be co-hosted by another entity(ies). For example,the example return path data 100 may be collected from the example mediapresentation devices 106 by a media provider (e.g., a cable televisionprovider, a satellite television provider, etc.) and the example meterdata 102 may be collected from an LPM (e.g., such as the example LPM112) by the example audience measurement entity 114 cooperating with themedia provider to gain access to the tuning data. The example audiencemeasurement entity 114 includes the example return path data audiencestorage 118 (e.g., a database) and the example panelist data storage 120(e.g., a database).

The example media output device 110 of FIG. 1 is a device capable ofoutputting the received media. For example, the media output device 110may be a television, a radio, speakers, a projector, a computer, acomputing device, a tablet, a mobile device, and/or any other devicecapable of outputting media. In some examples, the media output device110 receives media over-the-air. In this manner, the media output device110 receives media via an antenna, which may not be limited to receivingmedia from just one media provider. In the illustrated example of FIG.1, the media output device 110 corresponds to one or more monitoredpanelists. The example LPM 112 monitors panelist exposure to mediaoutput by the example media output device 110. For example, the exampleLPM 112 is in communication with the example media output device 110 tocollect and/or capture signals emitted externally by the media outputdevice 110. The LPM 112 may be coupled with the media output device 110via wired and/or wireless connection. The example LPM 112 may beimplemented in connection with additional and/or alternative types ofmedia presentation devices, such as, for example, a radio, a computermonitor, a video game console, and/or any other device capable topresent media to a user. The LPM 112 may be a portable people meter, acell phone, a computing device, a sensor, and/or any other devicecapable of metering (e.g., monitoring) user exposure to media. In someexamples, a media presentation location may include a plurality of LPMs112. In such examples, the plurality of the LPMs 112 may be used tomonitor media exposure for multiple users and/or media output devices110. Additionally, the example panelist data storage 120 receives andstores the example meter data 102 from the example LPM 112.

In some examples, the example LPM 112 of FIG. 1 includes a set ofbuttons assigned to audience members to determine which of the audiencemembers is watching the example media output device 110. The LPM 112 mayperiodically prompt the audience members via a set of LEDs, a displayscreen, and/or an audible tone, to indicate that the audience member ispresent at a first media presentation location by pressing an assignedbutton. In some examples, to decrease the number of prompts and, thus,the number of intrusions imposed upon the media consumption experienceof the audience members, the LPM 112 prompts only when unidentifiedaudience members are located at the first media presentation locationand/or only after the LPM 112 detects a channel change and/or a changein state of the media output device 110. In other examples, the LPM 112may include at least one sensor (e.g., a camera, 3-dimensional sensor,etc.) and/or be communicatively coupled to at least one sensor thatdetects a presence of the user in a first example media presentationlocation. The example LPM 112 transmits the example meter data 102 to amedia researcher and/or a marketing entity. The example meter data 102includes the media presentation data (e.g., data related to mediapresented while the media output device 110 is on and a user ispresent). The example meter data 102 may further include a householdidentification, a tuner key, a presentation start time, a presentationend time, a channel key, etc. Although the illustrated exampleillustrates the example audience measurement entity 114 collecting theexample meter data 102 from one LPM 112 at one location, the exampleaudience measurement entity 114 may collect meter data from any numberor type of meters at any number of locations.

The example return path data 100 (e.g., after post-processing) of FIG. 1from the example media presentation device 106 and/or the example meterdata 102 from the example LPM 112 is transmitted to the example audiencemeasurement entity 114 via a network. The network may be implementedusing any type of public or private network, such as, but not limitedto, the Internet, a telephone network, a local area network (LAN), acable network, and/or a wireless network. To enable communication viathe network, the example media presentation device 106 includes acommunication interface that enables a connection to an Ethernet, adigital subscriber line (DSL), a telephone line, a coaxial cable, or anywireless connection, etc.

The example modeler 116 of the example AME 114 of FIG. 1 collects theexample return path data 100 corresponding to the example mediapresentation device(s) 106. As described above, the example return pathdata 100 includes tuning data of the example media presentation device106. However, the example return path data 100 may not include specificdata identifying any information relating to the audience of the examplemedia output device 108. The example modeler 116 models such audienceinformation. For example, the modeler 116 may assign and/or modelvirtual users to augment the example return path data 100, therebygenerating audience (e.g., viewer or listener) assigned return pathdata. The example modeler 116 outputs the audience assigned return pathdata to the example return path data audience storage 118.

The example seed panel generator 122 of FIG. 1 gathers (A) the audienceassigned return path data from the example return path data audiencestorage 118, (B) the example meter data 102 from the example panelistdata storage 120, (C) and station data from the example station datastorage 124 to generate a seed panel. As explained above, a seed panelis a panel including synthetic respondent level data obtained frommonitored panelists corresponding to the LPM(s) 112, which are selectedbased on a return path data audience and/or homes and regional panelaudience and/or homes that are not covered by return path data. The seedpanelists are selected to represent the entire market. The example seedpanel generator 122 assigns geography and income data to the personsand/or homes corresponding to the audience assigned return path data andthe meter data 102. The example seed panel generator 122 initiates theseed panel by selecting monitored panelists to be representative of theviewer/geography/income assigned return path data audience. For example,a monitored panelist may be selected based on a similarity between (A)the location of the monitored panelist and the location of a return pathdata audience member, (B) demographics corresponding to the location ofthe return path data audience member and the demographics of themonitored panelist, (C) media viewing characteristics of the return pathdata audience and the monitored panelist, etc.

The example station data storage 124 stores data related to stationreceivability by county. The example seed panel generator 122 uses thestation data to calculate the station receivability for over the airhomes. In some examples, the seed panel generator 122 filters thegathered seed panelists to collect attributes of interest at the personlevel and/or the household level. Attributes of interest at the personlevel may include age, gender, ethnicity, nationality, race, etc., andattributes at the household level may include head of household data,cable data, single set data, Alternate Delivery System (ADS) data,county data, metro data, income, zip code, number of televisions, payservice data, etc. The example seed panel generator 122 weights the seedpanelists according to the universe estimate(s) of the designated marketarea. The universe estimate is an estimate of the total number of usersin a universe of users (e.g., total number of television viewers). Insome examples, the universe estimate is broken down at the demographiclevel. In some examples, when out-of-tab seed panelists exist, theexample seed panel generator 122 donates viewing based on a donor poolof seed panelists and/or monitored panelists of similar demographics. Aseed panelist is out-of-tab when, for example, the panelist's LPM 112 isoff, broken, and/or otherwise faulty. Additionally, the example seedpanel generator 122 may replicate and/or down-sample seed panelistsaccording to a replication parameter to increase and/or decrease thedegrees of freedom of the final seed panel. The example seed panelgenerator 122 replicates seed panelists by splitting seed panelists intotwo or more seed panelists whose weight is distributed among the tworepresentative seed panelists. The example seed panel generator 122down-samples the seed panelists by combining demographically similarseed panelists by combining the weight of the two or more seedpanelists. The example seed panel generator 122 stores the final seedpanel in the example seed panel storage 126.

The example synthetic panel generator 128 of FIG. 1 generates asynthetic panel from the seed panel generated by the example seed panelgenerator 122 to satisfy target reach constraints (e.g., daily, weekly,monthly, etc.) corresponding to the available (e.g., input) aggregatedata related to media. To generate a synthetic panel for a firstduration of time (e.g., a day), the synthetic panel generator 128generates a transition matrix representative of the probability ofpanelists changing from first media (e.g., a first channel, program,network, etc.) to second media (e.g., a second channel, program,network, etc.) for different quarter hours of the day. In some examples,the transition matrix may be broken up into multiple transition matricescorresponding to multiple demographics to identify the demographics ofthe synthetic panelists. The example synthetic panel generator 128generates viewing data for the seed panelists based on the transitionmatrices. The example synthetic panel generator 128 performs aniterative proportional fitting operation to generate weights for theseed panelists based on first duration (e.g., daily) constraints. Theexample synthetic panel generator 128 reduces the seed panel to a numberof daily synthetic panelists by removing any seed panelist whose weightis below a minimum weight threshold. In this manner, the examplesynthetic panel generator 128 generates a daily synthetic panel thatsatisfies the daily constraints. The daily synthetic panel includessynthetic respondent level data corresponding to the day.

Additionally, to generate a synthetic panel including syntheticrespondent level data for a second duration of time (e.g., a week, amonth, etc.) longer than the first duration of time (e.g., a day), theexample synthetic panel generator 128 of FIG. 1 gathers the dailysynthetic panels for days corresponding to the second duration of timeand generates a synthetic panel for the longer duration by linking thedaily synthetic panelists across the second duration of time. Forexample, if the example synthetic panel generator 128 of FIG. 1 isgenerating a monthly synthetic panel, the synthetic panel generator 128gathers the generated daily synthetic panels for days corresponding tothe month. However, the panelists included in daily synthetic panelsvary for different days. For example, different days may include adifferent order of synthetic panelists and/or completely differentsynthetic panelists. Accordingly, the example synthetic panel generator128 links daily synthetic panels across all days in the second duration(e.g., the month), regardless of whether a linked panelist is the reallythe same panelist. To optimize or otherwise improve the syntheticpanelist links, the example synthetic panel generator 128 linkspanelists using a Markov chain for different days to best match themonthly constraints. The example synthetic panel generator 128 isfurther described below in conjunction with FIGS. 2-4.

The example output file 130 of FIG. 1 includes the generated syntheticpanel (e.g., daily, weekly, monthly, etc.) including the viewing data ofthe generated synthetic panel. Additionally, the output file 130 mayinclude detailed demographic data of the synthetic panel, syntheticrespondent level attributes, quarter hour ratings calculated from thesynthetic respondent level data, daypart ratings calculated from thesynthetic respondent level data, daypart reach calculated from thesynthetic respondent level data, etc. Such data may be used to generatea report and/or may be further processed by a device (e.g., to estimatedata related to the universe of users).

FIG. 2 is a block diagram of an example implementation of the examplesynthetic panel generator 128 of FIG. 1 to generate the example outputfile 130 including synthetic respondent level data based on the seedpanel and aggregate level constraints. The example synthetic panelgenerator 128 includes an example daily synthetic panel generator 200,example daily constraints storage 202, example daily synthetic panelstorage 204, an example extended synthetic panel generator 206, exampleextended constraints storage 208, example extended synthetic panelstorage 210, and an example output file generator 212.

The example daily synthetic panel generator 200 of FIG. 2 receives theseed panel from the example seed panel storage 122 and generates a dailysynthetic panel based on daily constraints from the example dailyconstraints storage 202. In some examples, the daily synthetic panelgenerator 200 may generate a synthetic panel according to a differentduration of time (e.g., an hour, a half day, etc.) based on constraintscorresponding to that duration of time. As described above, the dailyconstraints include input reach constraints for the day based onaggregated return path data. For example, the daily constraints mayinclude a total number of viewers (e.g., based on return path data froma particular market, geographic area, etc.) that were exposed toprograms, channels in a channel lineup, networks, etc., within the day.Accordingly, the daily synthetic panel generator 200 generates dailysynthetic panels based on return path data reported by a plurality ofmedia devices, where the daily synthetic panels are representative ofaudiences of media provided by the plurality of media devices during aparticular day. The example daily synthetic panel generator 200generates a daily synthetic panel such that the daily synthetic panel,when weighted, corresponds to the daily constraints. In this manner, theweighted daily synthetic panel correspond to the aggregate data of theday. The example daily synthetic panel generator 200 generates thesynthetic panelists and their viewing data based on a transition matrixand an iterative reduction of panelists based on weights that satisfy athreshold. The example daily synthetic panel generator 200 is furtherdescribed below in conjunction with FIG. 3. The example daily syntheticpanel generator 200 stores the daily synthetic panels in the exampledaily synthetic panel storage 204.

The example extended synthetic panel generator 206 of FIG. 2 generatesan extended synthetic panel corresponding to an extended duration oftime (e.g., a duration of time longer than a day) based on (A) extendedconstraints stored in the example extended constraints storage 208 and(B) the daily synthetic panels (e.g., stored in the example dailysynthetic panel storage 204) corresponding the extended duration oftime. For example, the extended synthetic panel generator 206 maygenerate a weekly synthetic panel, a biweekly synthetic panel, a monthlysynthetic panel, etc. The example extended constraints include aggregatedata (e.g., reach corresponding to the extended duration of time asdetermined from the return path data). The example extended syntheticpanel generator 206 generates the extended synthetic panel by linkingpanelists in the daily synthetic panel across the extended duration oftime. Because the daily panelists that make up the daily syntheticpanels may be different for different days, the example extendedsynthetic panel generator 206 links the panelist in the daily panelsacross all the daily panels in the extended period to generate theextended synthetic panel within a demographic (e.g., location, age,gender, ethnicity, etc.). For example, the extended synthetic panelgenerator 206 may link (e.g., associate) a first panelist from a firstdaily synthetic panel to a second panelist from a second daily syntheticpanel, a third panelist from a third daily synthetic panel, etc., wherethe first panelist, second panelist, third panelist, etc., represent oneor more persons of a demographic in the extended duration of time, butare not necessarily the same seed panelist but are used to represent thesame synthetic panelist across the extended duration of time. Todetermine an optimal panelist linkage across the extended duration oftime, the example extended synthetic panel generator 206 calculates aconstraint error for panelist links for different days of the extendedduration of time. The example extended synthetic panel generator 206tests all possible link permutations for panelists within a demographicgroup for different days of the extended duration of time and selectsthe synthetic panelist links that correspond to the lowest constrainterror. The example extended synthetic panel generator 206 is furtherdescribed below in conjunction with FIG. 4. The example extendedsynthetic panel generator 206 stores the daily synthetic panels in theexample extended synthetic panel storage 210.

The example output file generator 212 of FIG. 2 gathers the dailysynthetic panels from the example daily synthetic panel storage 204and/or extended synthetic panel storage from the example extendedsynthetic panel storage 210 to generate the example output file 130. Theexample output file generator 212 generates the output file 130 toinclude synthetic respondent level data including at least one ofdetailed demographic data of the synthetic panel, synthetic respondentlevel attributes, quarter hour ratings calculated from the syntheticrespondent level data, daypart ratings calculated from the syntheticrespondent level data, daypart reach calculated from the syntheticrespondent level data, etc. As described above, such data may be used togenerate a report and/or may be further processed by a device (e.g., toestimate data related to the universe of users).

FIG. 3 is block diagram of an example implementation of the exampledaily synthetic panel generator 200 of FIG. 2 to generate a syntheticpanel corresponding to a first duration of time (e.g., a day). Theexample daily synthetic panel generator 200 includes an exampletransition data determiner 300, an example synthetic panelist determiner302, and an example weighter 304.

The example transition data determiner 300 of FIG. 3 generates atransition matrix representative of the probability of seed panelistschanging from a first media (e.g., a first channel) to a second media(e.g., a second channel) for different quarter hours of the day based onthe seed panel stored in the example seed panelist storage 126 ofFIG. 1. The example transition data determiner 300 generates atransition matrix per quarter hour. According, the example transitiondata determiner 300 generates 96 transition matrices for a dailysynthetic panel.

The example synthetic panelist determiner 302 of FIG. 3 generatesinitial synthetic panelists based on the transition matrix generated bythe example transition data determiner 300. The example syntheticpanelist determiner 302 selects an initial number of synthetic panelistand generates viewing data for the initial number of syntheticpanelists. To initialize the viewing data, the example syntheticpanelist determiner 302 randomly picks a station (e.g., channel) that isviewed for the first quarter hour for a first synthetic panelist. Insome examples, the initial station is picked based on an expecteddistribution of stations at the first quarter hour. The examplesynthetic panelist determiner 302 uses the data in the generatedtransition matrix (e.g., the probability that a panelist will switch toa second channel) to determine which channel the first syntheticpanelist is viewing at a second quarter hour, a third quarter hour, . .. , and a ninety-sixth quarter hour (e.g., making up the viewing datafor the first synthetic panelist for the day). This process is repeatedfor other synthetic panelists until the example synthetic panelistdeterminer 302 generates the viewing data for the initial number of thesynthetic panelists. Once, the viewing data for the synthetic panelistshave been generated, the viewing data may not correspond (e.g., match)the daily constraints (e.g., the daily reach) from the example dailyconstraints storage 202. As further described below, the exampleweighter 304 weights the viewing data of the synthetic panelists so thatthe viewing data better matches the daily constraints. Additionally,after the synthetic panelist determiner 302 determines a final syntheticpanel (e.g., based on the below described technique), the syntheticpanelist determiner 302 stores the daily synthetic panel including theviewing data in the example daily synthetic panel storage 204.

The example weighter 304 of FIG. 4 performs iterative proportionalfitting to determine weights for the viewing data of the initialsynthetic panel so that the weighted viewing data matches the aggregatereach constraints. After the example weighter 304 weights the viewing ofinitial synthetic panel, the synthetic panel may still not match thedaily constraints from the example daily constraint storage 202 of FIG.2. Accordingly, the example synthetic panelist determiner 302 removesinitial synthetic panelists (and corresponding demographic and viewingdata) whose weights are below a minimum weight threshold (e.g.,corresponding to synthetic panelists that don't match well with theconstraints). The example weighter 304 reweighs the reduced syntheticpanel and the process repeats until the weights converge, therebygenerating the final daily synthetic panel that matches the dailyconstraints (e.g., the best fit or sample of panelists that satisfy thedaily constraints). The sum of the resulting weights is constant fromday to day. Accordingly, the resulting daily synthetic panel for eachday with have the same number of divided panelists from day to day.

FIG. 4 is block diagram of an example implementation of the exampleextended synthetic panel generator 206 of FIG. 2 to generate an extendedsynthetic panel. The example extended synthetic panel generator 206includes an example panelist combiner 400 and an example constrainterror determiner 402.

The example panelist combiner 400 of FIG. 4 gathers daily syntheticpanels corresponding to an extended duration of time (e.g., a durationof time made up of any number of days). As described above, thesynthetic panelists used in a first daily synthetic panel may not be thesame synthetic panelists used in a second daily synthetic panel.Accordingly, the example panelist combiner 400 links (e.g., combines)panelists from daily synthetic panels across the extended duration oftime. The example panelist combiner 400 may first determine thedemographics of the daily synthetic panelists and group the panelists bya demographic (e.g., age, gender, location, ethnicity, etc.). Theexample panelist combiner 400 may link panelists whose demographicmatches. In some examples, the panelist combiner 400 equalizes theweights of the panelists prior to linking the panelists across days. Thepanelist combiner 400 equalizes the weights to ensure that the samenumber of panelists are linked across days. Additionally, the linkingoptimization is simplified when the weights are equalized.

To generate the links, the example panelist combiner 400 of FIG. 4determines possible permutations of synthetic panelist links within ademographic group between a first day and a second day. Once thepermutations have been determined, the example constraint errordeterminer 402 determines the constraint error of different permutationsof the synthetic panelist links (e.g., based on the return path data).In some examples, the constraint error determiner 402 determines theconstraint error by calculating a first reach corresponding to thesynthetic panelist link and compares (e.g., subtracts) the first reachdetermined by combining viewing data for synthetic panelist according tosynthetic panelist links to a second reach corresponding to theaggregate data (e.g., a target reach) based on the return path data inthe example extended constraints storage 208. The example panelistcombiner 400 links the panelist based on the permutations with thesmallest constraint error. Once the example panelist combiner 400determines the panelist links for the first and second day, the processrepeats for a third day, a fourth day, etc. until the panelists arelinked across all days in the extended duration of time. In someexamples, if the constraint error is not zero or below a maximum errorthreshold, the process repeats until the extended constraint error isproperly minimized. Once the extended constraint error is minimized orotherwise reduced, the example panelist combiner 400 stores the extendedsynthetic panel (e.g., including corresponding demographic data andviewing data) in the example extended synthetic panel storage 210.

While an example manner of implementing the example synthetic panelgenerator 128 of FIG. 1 is illustrated in FIGS. 2-4, one or moreelements, processes and/or devices illustrated in FIGS. 2-4 may becombined, divided, re-arranged, omitted, eliminated and/or implementedin any other way. Further, the example daily synthetic panel generator200, the example extended synthetic panel generator 206, the exampleoutput fil generator 212, the example transition data determiner 300,the example synthetic panelist determiner 302, the example weighter 304,the example panelist combiner 400, the example constraint errordeterminer 402, and/or, more generally, the example the example panelistreplicator 212, of FIGS. 2-4 may be implemented by hardware, machinereadable instructions, software, firmware and/or any combination ofhardware, machine readable instructions, software and/or firmware. Thus,for example, any of the example daily synthetic panel generator 200, theexample extended synthetic panel generator 206, the example output filgenerator 212, the example transition data determiner 300, the examplesynthetic panelist determiner 302, the example weighter 304, the examplepanelist combiner 400, the example constraint error determiner 402,and/or, more generally, the example the example panelist replicator 212,of FIGS. 2-4 could be implemented by one or more analog or digitalcircuit(s), logic circuit(s), programmable processor(s), applicationspecific integrated circuit(s) (ASIC(s)), programmable logic device(s)(PLD(s)) and/or field programmable logic device(s) (FPLD(s)). Whenreading any of the apparatus or system claims of this patent to cover apurely software and/or firmware implementation, at least one of theexample daily synthetic panel generator 200, the example extendedsynthetic panel generator 206, the example output fil generator 212, theexample transition data determiner 300, the example synthetic panelistdeterminer 302, the example weighter 304, the example panelist combiner400, the example constraint error determiner 402, and/or, moregenerally, the example the example panelist replicator 212, of FIGS. 2-4is/are hereby expressly defined to include a tangible computer readablestorage device or storage disk such as a memory, a digital versatiledisk (DVD), a compact disk (CD), a Blu-ray disk, etc., storing thesoftware and/or firmware. Further still, the example synthetic panelgenerator 128 of FIGS. 2-4 may include one or more elements, processesand/or devices in addition to, or instead of, those illustrated in FIGS.2-4, and/or may include more than one of any or all of the illustratedelements, processes and devices.

Flowcharts representative of example machine readable instructions forimplementing the example synthetic panel generator 128 of FIGS. 2-4 areshown in FIGS. 5-7. In the examples, the machine readable instructionscomprise a program for execution by a processor such as the processor812 shown in the example processor platform 800 discussed below inconnection with FIG. 8. The program may be embodied in software storedon a tangible computer readable storage medium such as a CD-ROM, afloppy disk, a hard drive, a digital versatile disk (DVD), a Blu-raydisk, or a memory associated with the processor 812, but the entireprogram and/or parts thereof could alternatively be executed by a deviceother than the processor 812 and/or embodied in firmware or dedicatedhardware. Further, although the example program is described withreference to the flowcharts illustrated in FIGS. 5-7, many other methodsof implementing the example synthetic panel generator 128 of FIGS. 2-4may alternatively be used. For example, the order of execution of theblocks may be changed, and/or some of the blocks described may bechanged, eliminated, or combined.

As mentioned above, the example process of FIGS. 5-7 may be implementedusing coded instructions (e.g., computer and/or machine readableinstructions) stored on a tangible computer readable storage medium suchas a hard disk drive, a flash memory, a read-only memory (ROM), acompact disk (CD), a digital versatile disk (DVD), a cache, arandom-access memory (RAM) and/or any other storage device or storagedisk in which information is stored for any period (e.g., for extendedtime periods, permanently, for brief instances, for temporarilybuffering, and/or for caching of the information). As used herein, theterm tangible computer readable storage medium is expressly defined toinclude any type of computer readable storage device and/or storage diskand to exclude propagating signals and to exclude transmission media. Asused herein, “tangible computer readable storage medium” and “tangiblemachine readable storage medium” are used interchangeably. Additionallyor alternatively, the example process of FIGS. 5-7 may be implementedusing coded instructions (e.g., computer and/or machine readableinstructions) stored on a non-transitory computer and/or machinereadable medium such as a hard disk drive, a flash memory, a read-onlymemory, a compact disk, a digital versatile disk, a cache, arandom-access memory and/or any other storage device or storage disk inwhich information is stored for any period (e.g., for extended timeperiods, permanently, for brief instances, for temporarily buffering,and/or for caching of the information). As used herein, the termnon-transitory computer readable medium is expressly defined to includeany type of computer readable storage device and/or storage disk and toexclude propagating signals and to exclude transmission media. As usedherein, when the phrase “at least” is used as the transition term in apreamble of a claim, it is open-ended in the same manner as the term“comprising” is open ended.

FIG. 5 is an example flowchart 500 representative of example machinereadable instructions that may be executed by the example syntheticpanel generator 128 of FIGS. 1 and 2 to generate the example output file130 to include synthetic respondent level data. Although theinstructions of FIG. 5 are described in conjunction with the examplesynthetic panel generator 128 of FIGS. 1 and 2, the example instructionsmay be utilized by any type of synthetic panel generator. Although, theflowcharts 500, 504, 506 of FIGS. 5, 6, and 7 are described inconjunction with generating synthetic respondent level datacorresponding to daily and monthly durations, the synthetic respondentlevel data may correspond to any durations of time.

At block 502, the example daily synthetic panel generator 200 receivesseed panel data from the example seed panel storage 126 of FIG. 1. Atblock 504, the example daily synthetic panel generator 200 generatesdaily synthetic respondent level data based on the received seed paneldata and daily reach constraints. The generation of the daily syntheticrespondent level data is further described below in conjunction withFIG. 6. At block 506, the example extended synthetic panel generator 206generates monthly synthetic respondent level data based on an optimallinkage (e.g., a linkage that reduces constraint error) of dailysynthetic panelists corresponding to a month. The generation of monthlysynthetic respondent level data is further described below inconjunction with FIG. 7. At block 508, the example output file generator212 generate the example output file 130 including the daily syntheticrespondent level data and/or the monthly synthetic respondent leveldata.

FIG. 6 is an example flowchart 504 representative of example machinereadable instructions that may be executed to implement the exampledaily synthetic panel generator 200 of the example synthetic panelgenerator 128 of FIG. 2 to generate daily synthetic respondent leveldata based on seed panel data and daily reach constraints, as describedabove in conjunction with block 504 of FIG. 5. Although the instructionsof FIG. 5 are described in conjunction with the example daily syntheticpanel generator 200 of FIG. 2, the example instructions may be utilizedby any type of daily synthetic panel generator.

At block 600, the example transition data determiner 300 generates atransition matrix for quarter hours for a first duration of time (e.g.,a day). As further described above in conjunction with FIG. 2, thetransition matrix is based on the seed panel and represents theprobability that a panelist will change channels, stations, progress,etc. in a given quarter hour. At block 602, the example syntheticpanelist determiner 302 generates an initial synthetic panelist. Atblock 604, the example synthetic panelist determiner 302 assigns aninitial viewing program for the generated synthetic panelist for firstquarter hour of the day. In some examples, the synthetic panelistdeterminer 302 assigns the initial viewing program based on an expecteddistribution of programs at the first quarter hour.

At block 606, the example synthetic panelist determiner 302 assigns asubsequent viewing program for the generate synthetic panelist for asubsequent quarter hour of the day based on the transition matrix. Theexample synthetic panelist determiner 302 may generate a randomly selecta program based on the transition matrix for the first quarter hour thatidentifies the probability that a panelist will change the program to adifferent program. For example, if the transition matrix corresponds toa 50% chance that a person watching NBC at the beginning of the firstquarter hour will remain on NBC during the entire first quarter hour, a30% chance that the person will change to ABC during the first quarterhour, and a 20% chance that the person will change to CBS during thefirst quarter hour and the first synthetic panelist has been initializedas watching NBC, the example synthetic panelist determiner 302 willrandomly select a viewing program for the first quarter, where therandomly selected viewing program has a 50% chance of being NBC, a 30%chance of being ABC, and a 20% chance of being CBS.

At block 608, the example synthetic panelist determiner 302 determinesif the viewing programs have been determined for all quarter hours forthe synthetic panelist. If the example synthetic panelist determiner 302determines that the viewing programs have not been determined for allquarter hours (block 608: NO), the process returns to block 606 todetermine viewing programs for subsequent quarter hours. If the examplesynthetic panelist determiner 302 determines that the viewing programshave been determined for all quarter hours (block 608: YES), the examplesynthetic panelist determiner 302 determines if the maximum number ofsynthetic panelists has been generated (block 610).

If the example synthetic panelist determiner 302 determines that themaximum number of synthetic panelists has not been generated (block 610:NO), the process returns to block 602 to generate a subsequent syntheticpanelist until the maximum number of synthetic panelists has beengenerated. If the example synthetic panelist determiner 302 determinesthat the maximum number of synthetic panelists has been generated (block610: YES), the example weighter 304 determines weights for the syntheticpanelists viewing patterns (e.g., assigned viewing data at the differentquarter hours) (block 612). The example weighter 304 weights thesynthetic panelists to correspond to the daily constraints. As describedabove, the example weighter 304 may determine the weights by performingan iterative proportional fitting operation.

At block 614, the example synthetic panelist determiner 302 determinesif any of the determined weights are below a minimum threshold. Lowweights (e.g., below a minimum threshold) correspond to syntheticpanelists that are not good fits for the daily constraints. If theexample synthetic panelist determiner 302 determines that there is adetermined weight(s) below the minimum threshold (block 614: YES), theexample synthetic panelist determiner 302 removes the syntheticpanelists corresponding to weights below the minimum threshold (block616). In this manner, the remaining synthetic panelists correspond to abetter fit for the daily constraints. The process returns to block 612to reweigh the remaining panelists and/or remove additional panelistsuntil the remaining panelists corresponds to weights above the minimumthreshold.

If the example synthetic panelist determiner 302 determines that thereare no determined weights below the minimum threshold (block 614: NO),the example weighter 304 generates daily synthetic panel by applying theweights to the viewing data of the remaining synthetic panelists (block618). At block 620, the example daily synthetic panel storage 204 (FIG.2) stores the remaining synthetic panelists (including demographics ofthe remaining synthetic panelists) and corresponding viewing data as afinal synthetic panelist corresponding to the day (e.g., daily syntheticrespondent level data).

FIG. 7 is an example flowchart 506 representative of example machinereadable instructions that may be executed to implement the exampleextended synthetic panel generator 206 of the example synthetic panelgenerator 128 of FIG. 4 to generate monthly synthetic respondent leveldata based on an optimal synthetic panel linkage of the daily syntheticpanelists corresponding to the month, as described above in conjunctionwith block 506 of FIG. 5. Although the instructions of FIG. 5 aredescribed in conjunction with the example extended synthetic panelgenerator 206 of FIG. 2, the example instructions may be utilized by anytype of daily synthetic panel generator. Additionally, although theinstructions of FIG. 5 are described in conjunction with the extendedperiod of time being a month, any duration of time longer than a day maybe used for the extended period of time.

At block 700, the example panelist combiner 400 equalizes the weights ofthe daily synthetic panel corresponding to a month. At block 702, theexample panelist combiner 400 groups synthetic panelists according to ademographic and are used to represent a same synthetic panelist acrossthe monthly duration. The demographic may be based on user and/ormanufacture preferences. For example, the demographic may be location ofthe synthetic panelist. Accordingly, the example panelist combiner 400groups the synthetic panelists of daily synthetic panels according tolocation (e.g., by state or city, for example).

At block 704, the example panelist combiner 400 links panelists acrossdaily panels corresponding to the month within the demographic groups.For example, a first synthetic panelist in a first daily panel is linkedto a second synthetic panelist in a second daily panel, a third panelistin a third synthetic panel, etc., where the first, second, and thirdpanelist correspond to the same demographic. At block 706, the exampleconstraint error determiner 402 calculates the monthly reach error(e.g., a monthly constraint error) based on the panelist links acrossthe daily panels corresponding to the month. The example constrainterror determiner 402 calculates the monthly reach error by combining(e.g., subtracting) the monthly reach corresponding to the syntheticpanelist links and the actual monthly reach constraint (e.g., the closerthe difference is to zero, the lower the error). In some examples, whenthe initial panelist links are selected arbitrarily, the monthly reacherror is relatively high.

At block 708, the example constraint error determiner 402 determines ifthe monthly reach error is below a maximum error threshold. The maximumerror threshold is the maximum allowable error for the monthly reach andmay be determined based on user and/or manufacture preferences. In someexamples, the maximum error threshold is zero. If the example constrainterror determiner 402 determines that the monthly reach error is notbelow a maximum error threshold (block 708: NO), the example panelistcombiner 400 selects two days corresponding to the month (e.g., a firstand second day of the month) (block 710).

At block 712, the example constraint error determiner 402 identifiesreach error for the different permutations of panelists links for theselected days within the demographic groups. For example, the exampleconstraint error determiner 402 calculates a first error for a firstlink between a first synthetic panelist in the first daily panel and asecond synthetic panelist in the second daily panel (e.g., the initialpanelist link) and calculates a second error for a second link betweenthe first synthetic panelist in the first daily panel and a thirdsynthetic panelist in the second daily panel, where the first, second,and third panelists correspond to the same demographic.

At block 714, the example panelist combiner 400 swaps panelist linkswithin demographic groups based on the highest reduction of error. Usingthe above example, if the second link reduces the error more than thefirst link, the example panelist combiner 400 swaps the panelists linksso that the first synthetic panelist of the first synthetic panel is nowlinked to the third synthetic panelist of the second synthetic panel.The process returns to block 708 and is rerun for different daily panelsuntil the optimal synthetic panelist links are formed (e.g., thesynthetic panelist links that reduce the reach error below the maximumerror threshold). If the example constraint error determiner 402determines that the monthly reach error is below a maximum errorthreshold (block 708: YES), the example panelist combiner 400 generatesa monthly synthetic panel based on the panelist links that correspondingwith a reach error below the maximum error threshold (block 716).

FIG. 8 is a block diagram of an example processor platform 800 capableof executing the instructions of FIGS. 5-7 to implement the examplesynthetic panel generator 128 of FIG. 1. The processor platform 800 canbe, for example, a server, a personal computer, a mobile device (e.g., acell phone, a smart phone, a tablet such as an iPad™), a personaldigital assistant (PDA), an Internet appliance, or any other type ofcomputing device.

The processor platform 800 of the illustrated example includes aprocessor 812. The processor 812 of the illustrated example is hardware.For example, the processor 812 can be implemented by integratedcircuits, logic circuits, microprocessors or controllers from anydesired family or manufacturer.

The processor 812 of the illustrated example includes a local memory 813(e.g., a cache). The example processor 812 of FIG. 8 executes theinstructions of FIGS. 5-7 to the example daily synthetic panel generator200, the example extended synthetic panel generator 206, the exampleoutput fil generator 212, the example transition data determiner 300,the example synthetic panelist determiner 302, the example weighter 304,the example panelist combiner 400, and/or the example constraint errordeterminer 402 to implement the example synthetic panel generator 128 ofFIG. 2. The processor 812 of the illustrated example is in communicationwith a main memory including a volatile memory 814 and a non-volatilememory 816 via a bus 818. The volatile memory 814 may be implemented bySynchronous Dynamic Random Access Memory (SDRAM), Dynamic Random AccessMemory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM) and/or anyother type of random access memory device. The non-volatile memory 816may be implemented by flash memory and/or any other desired type ofmemory device. Access to the main memory 814, 816 is controlled by amemory controller.

The processor platform 800 of the illustrated example also includes aninterface circuit 820. The interface circuit 820 may be implemented byany type of interface standard, such as an Ethernet interface, auniversal serial bus (USB), and/or a PCI express interface.

In the illustrated example, one or more input devices 822 are connectedto the interface circuit 820. The input device(s) 822 permit(s) a userto enter data and commands into the processor 812. The input device(s)can be implemented by, for example, a sensor, a microphone, a camera(still or video), a keyboard, a button, a mouse, a touchscreen, atrack-pad, a trackball, isopoint and/or a voice recognition system.

One or more output devices 824 are also connected to the interfacecircuit 820 of the illustrated example. The output devices 824 can beimplemented, for example, by display devices (e.g., a light emittingdiode (LED), an organic light emitting diode (OLED), a liquid crystaldisplay, a cathode ray tube display (CRT), a touchscreen, a tactileoutput device, and/or speakers). The interface circuit 820 of theillustrated example, thus, typically includes a graphics driver card, agraphics driver circuit or a graphics driver processor.

The interface circuit 820 of the illustrated example also includes acommunication device such as a transmitter, a receiver, a transceiver, amodem and/or network interface card to facilitate exchange of data withexternal machines (e.g., computing devices of any kind) via a network826 (e.g., an Ethernet connection, a digital subscriber line (DSL), atelephone line, coaxial cable, a cellular telephone system, etc.).

The processor platform 800 of the illustrated example also includes oneor more mass storage devices 828 for storing software and/or data.Examples of such mass storage devices 828 include floppy disk drives,hard drive disks, compact disk drives, Blu-ray disk drives, RAIDsystems, and digital versatile disk (DVD) drives.

The coded instructions 832 of FIGS. 5-7 may be stored in the massstorage device 828, in the volatile memory 814, in the non-volatilememory 816, and/or on a removable tangible computer readable storagemedium such as a CD or DVD.

From the foregoing, it should be appreciated that the above disclosedmethods, apparatus, and articles of manufacture generate syntheticrespondent level data. Example disclosed herein process the collectedand/or aggregated metering data for markets where a panel is maintainedand collect and/or aggregate return path data for markets where a panelis not maintained to generate a seed panel. Once a seed panel has beengenerated, examples disclosed herein generate a transition matrixcorresponding to the seed panel. The transition matrix is used togenerate viewing data for an initial daily synthetic panel that isadjusted based on daily constraints. Examples disclosed herein determineextended (e.g., weekly, monthly) synthetic respondent level data bylinking synthetic panelists from daily synthetic panels for the extendedtime period. The synthetic panelist links are optimized to satisfytarget monthly reach. Using examples disclosed herein, consistentrespondent level data is generated that satisfy various constraints,thereby providing more accurate universe estimations.

Although certain example methods, apparatus and articles of manufacturehave been described herein, the scope of coverage of this patent is notlimited thereto. On the contrary, this patent covers all methods,apparatus and articles of manufacture fairly falling within the scope ofthe appended claims either literally or under the doctrine ofequivalents.

1. An apparatus comprising: a daily synthetic panel generator togenerate, by executing an instruction with a processor, a firstsynthetic panel corresponding to a first duration of time and a secondsynthetic panel corresponding to a second duration of time, the firstsynthetic panel being based on (a) a seed panel and (b) first durationconstraints based on return path data reported by a plurality of mediadevices, the second synthetic panel being based on (a) the seed paneland (b) second duration constraints based on the return path datareported by the plurality of media devices, the first synthetic panelrepresentative of audiences of media presented by the plurality of mediadevices during the first duration of time, the second synthetic panelrepresentative of audiences of media presented by the plurality of mediadevices during the second duration of time; an extended synthetic panelgenerator to generate, by executing an instruction with the processor,synthetic respondent level data corresponding to a third duration oftime by linking first synthetic panelists in the first synthetic panelto second synthetic panelist in the second synthetic panel; and anoutput file generator to generate an output file based on the syntheticrespondent level data.
 2. The apparatus of claim 1, wherein the dailysynthetic panel generator is to generate the first synthetic panel by:generating a transition matrix corresponding to the first and seconddurations of time, the transition matrix being based on the seed panel;generating viewing data for the first synthetic panelists correspondingto the first and second durations of time, the viewing data beinggenerated using the transition matrix; determining weights to apply tothe viewing data for the first synthetic panelists to satisfy the firstduration constraints; and removing one or more of the first syntheticpanelists whose weights do not satisfy a minimum threshold.
 3. Theapparatus of claim 2, wherein the transition matrix corresponds to aprobability that a panelist will change stations during a quarter hour.4. The apparatus of claim 2, wherein the first synthetic panelists arereweighted after the one or more of the first synthetic panelists havebeen removed.
 5. The apparatus of claim 1, wherein the first durationconstraints include reaches for the first duration corresponding toaggregate reach data determined based on the return path data.
 6. Theapparatus of claim 5, wherein the extended synthetic panel generator isto generate the synthetic respondent level data corresponding to thethird duration of time by: determining a duration constraint errorcorresponding to a comparison of a first reach for the second durationdetermined by combining viewing data for synthetic panelists accordingto the synthetic panelist links and a second reach for the secondduration corresponding to aggregate reach data determined based on thereturn path data; and when the duration constraint error does notsatisfy an error threshold, swapping the synthetic panelist links toreduce the duration constraint error.
 7. The apparatus of claim 6,wherein the swapping of the synthetic panelist links includes:identifying the duration constraint error for permutations of panelistlinks between the first synthetic panel and the second synthetic panel;and swapping the synthetic panelist links based on a highest reductionof the duration constraint error.
 8. The apparatus of claim 1, whereinthe synthetic panelists are linked according to a demographic.
 9. Theapparatus of claim 1, wherein the first duration of time corresponds toa first day, the second duration of time corresponds to a second day,and the third duration of time corresponds to a duration of timeincluding the first and second days.
 10. A method comprising:generating, by executing an instruction with a processor, a firstsynthetic panel corresponding to a first duration of time and a secondsynthetic panel corresponding to a second duration of time, the firstsynthetic panel being based on a (a) seed panel and (b) first durationconstraints based on return path data reported by a plurality of mediadevices, the second synthetic panel being based on (a) the seed paneland (b) second duration constraints based on the return path datareported by the plurality of media devices, the first synthetic panelrepresentative of audiences of media presented by the plurality of mediadevices during the first duration of time, the second synthetic panelrepresentative of audiences of media presented by the plurality of mediadevices during the second duration of time; generating, by executing aninstruction with the processor, synthetic respondent level datacorresponding to a third duration of time by linking first syntheticpanelists in the first synthetic panel to second synthetic panelist inthe second synthetic panel; and generating an output file based on thesynthetic respondent level data.
 11. The method of claim 10, wherein thegenerating of the first synthetic panel includes: generating atransition matrix corresponding to the first and second durations oftime, the transition matrix being based on the seed panel; generatingviewing data for the first synthetic panelists corresponding to thefirst and second durations of time, the viewing data being based on thetransition matrix; determining weights to apply to the viewing data forthe first synthetic panelists to satisfy the first duration constraints;and removing one or more of the first synthetic panelists whose weightsdo not satisfy a minimum threshold.
 12. The method of claim 11, whereinthe transition matrix corresponds to a probability that a panelist willchange stations during a quarter hour.
 13. The method of claim 11,wherein the first synthetic panelists are reweighted after the one ormore of the first synthetic panelists have been removed.
 14. The methodof claim 10, wherein the first duration constraints include reaches forthe first duration corresponding to aggregate reach data determinedbased on the return path data.
 15. The method of claim 14, wherein thegenerating of the synthetic respondent level data corresponding to thethird duration of time includes: determining a duration constraint errorcorresponding to a comparison of a first reach for the second durationdetermined by combining viewing data for synthetic panelists accordingto the synthetic panelist links and a second reach for the secondduration corresponding to aggregate reach data determined based on thereturn path data; and when the duration constraint error does notsatisfy an error threshold, swapping the synthetic panelist links toreduce the duration constraint error.
 16. The method of claim 15,wherein the swapping of the synthetic panelist links includes:identifying the second duration constraint error for permutations ofpanelist links between the first synthetic panel and the secondsynthetic panel; and swapping the synthetic panelist links based on ahighest reduction of the duration constraint error.
 17. The method ofclaim 10, wherein the synthetic panelists are linked according to ademographic.
 18. The method of claim 10, wherein the first duration oftime corresponds to a first day, the second duration of time correspondsto a second day, and the third duration of time corresponds to aduration of time including the first and second days.
 19. A tangiblecomputer readable storage medium comprising instructions which, whenexecuted, cause a machine to at least: generate, by executing aninstruction with a processor, a first synthetic panel corresponding to afirst duration of time and a second synthetic panel corresponding to asecond duration of time, the first synthetic panel being based on (a) aseed panel and (b) first duration constraints based on return path datareported by a plurality of media devices, the second synthetic panelbeing based on (A) the seed panel and (b) second duration constraintsbased on the return path data reported by the plurality of mediadevices, the first synthetic panel representative of audiences of mediapresented by the plurality of media devices during the first duration oftime, the second synthetic panel representative of audiences of mediapresented by the plurality of media devices during the second durationof time; generate, by executing an instruction with the processor,synthetic respondent level data corresponding to a third duration oftime by linking first synthetic panelists in the first synthetic panelto second synthetic panelist in the second synthetic panel; and generatean output file based on the synthetic respondent level data.
 20. Thecomputer readable storage medium of claim 19, wherein the instructionscause the machine to generate the first synthetic panel by: generating atransition matrix corresponding to the first and second durations oftime, the transition matrix being based on the seed panel; generatingviewing data for the first synthetic panelists corresponding to thefirst and second durations of time, the viewing data being based on thetransition matrix; determining weights to apply to the viewing data forthe first synthetic panelists to satisfy the first duration constraints;and removing one or more of the first synthetic panelists whose weightsdo not satisfy a minimum threshold. 21-27. (canceled)